/Engine/Plugins/Runtime/Metasound/Source/MetasoundFrontend/Public/MetasoundParameterPack.h
Here is theUObjectBlueprintType that can be used in c++ and blueprint code. It holds a FMetasoundParamStorage instance and can pass it along to the audio system's SetObjectParameter function via an AudioProxy.
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)(BlueprintType, Meta=(DisplayName="MetaSoundParameterPack")) class UMetasoundParameterPack : public [UObject](API\Runtime\CoreUObject\UObject\UObject), public [IAudioProxyDataFactory](API\Runtime\AudioExtensions\IAudioProxyDataFactory)